98 
Haemoflagellates, etc. 
externally. In the case of the rosette of Crithidia gerridis the flagella 
are similarly directed externally, while in the agglomeration of the adult 
flagellates the flagella are directed centrally. The explanation of the 
position of the flagella in a true multiplication rosette is always readily 
ascertained by studying the method of multiple segmentation. In our 
opinion the agglomerated cluster of male forms of T. noctuae from the 
intestine of Culex pipiens as figured by Schaudinn represents a true 
Herpetomonad rosette. We think it is of some importance for a 
beginner to have a clear conception of the difference between a true 
multiplication rosette of a Trypanosoma, Herpetomonas and Crithidia 
and a mere agglomeration of adult flagellates, which is quite a distinct 
process. 
It is not possible to say why adult vertebrate trypanosomes collect 
together (see p. 118) by their aflagellar ends under certain conditions. 
We have certainly not seen insect flagellates collect together by their 
aflagellar ends in the alimentary tracts of their hosts. 
Woodcock considers the abnormal and involution forms of trypano¬ 
somes are produced as a result of chromatolysis, vacuolisation and change 
of form. In the light of Salvin-Moore and Breinl’s recent work these 
round or oval bodies represent an important phase in the life cycle of a 
trypanosome; if this proves to be the case it opens up an entirely new 
field of research. 
We now propose dealing with the most important section of 
Woodcock’s article, the life cycles of trypanosomes, and we have pointed 
out above that it is intimately connected with the transmission of these 
parasites from one host to the other. When Woodcock wrote his first 
article on the Haemoflagellates Schaudinn’s observations on the life cycle 
of T. noctuae appeared to be amply corroborated by the brothers Sergent 
(1905), Billet (1904), Brumpt (1904), Leger (1904) and Rogers (1904); 
we do not see however what connection the parasite of Kala-Azar has 
with Schaudinn’s work and how Rogers’ discovery of its flagellate 
stage has corroborated it. Woodcock evidently still thinks this parasite 
is a Piroplasma in spite of recent researches. 
Since the publication of the paper by Novy and MacNeal (1905) 
describing valuable work on the trypanosomes of birds, Schaudinn’s work 
has been largely discredited. Influenced still further by their researches 
on mosquito flagellates, Novy and his collaborators have expressed the 
view that the Haemoflagellates and Haemosporidia are quite distinct, 
and that the trypanosomes of vertebrates do not undergo any develop¬ 
mental cycle in insect hosts. In spite of what Woodcock says to the 
